Reliable delivery of ammunition from an external supply into a firearm chamber is an important aspect of effective firearm operations. The structure and capacity of the external supply of ammunition may affect the consistency of ammunition delivery. Additionally, the ability of the external supply to be detached from the firearm, reloaded with ammunition, and then reused with the firearm may enhance the effectiveness of firearm operations. Although ammunition magazines (e.g., STANAG or STANAG-compatible box magazines) are known, some ammunition magazines may lack durability or tend to malfunction. Accordingly, a need exists for new ammunition storage and feeding devices.